Intel 386 - Manual (Page 64)

4-13
SYSTEM REGISTER ORGANIZATION
Figure 4-7. Enhanced DOS Mode
3FFH
0
On-chip DMA
0H
On-chip 8259A-1
On-chip UART-2
On-chip UART-1
On-chip 8259A-2
On-chip Timer
1
0 0 0 0 0 0 0 0
A2501-02
23H
22H
REMAPCFG
Register
DOS I/O Space
F000H
8259A-1
8259A-2
Timer
UART-1
UART-0
On-chip DMA
Other Peripherals
FFFFH
Expanded I/O Space